Iran's Bushehr nuclear reactor goes critical

Final commissioning tests will now be carried out prior to ramp-up to 100% power and the start of commercial operation. According to Iranian news agency Fars, the plant is expected to be connected to the national grid within the next two months.

It would normally take a few months after grid connection before a new nuclear reactor is operating at full commercial capacity.

The road to start-up still was not without hold-ups. In February 2011, only weeks before operation was expected to start, the discovery of debris from damaged coolant pumps meant that all the fresh reactor fuel had to be unloaded, checked and cleaned, and the reactor internals and main circulation pipeline flushed through.

The plant will initially be operated by a 50:50 Russian-Iranian joint venture, with Russia gradually withdrawing over the next three years.

Unlike the controversial parts of Iran's nuclear program, such as uranium enrichment and a heavy-water reactor, the Bushehr plant has been entirely built and will operate under full IAEA safeguards. It will produce about 1000 MWe for the Iranian grid, establishing nuclear power at about 3% of the country's power supply